Fire-extinguisher.



J. B THOMAS.

FIRE EXTINGUISHER.

APPLIGATLON FILED MAY 11, 1912.

1,Q38,026., Patented Sept. 10, 1912.

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JESSE B. THOMAS, 0F BOSTON, MASSACHUSETTS.

FIRE-EXTINGU'ISHER.

Specification of Letters Patent.

Application filed May 11, 1912.

Patented Sept. 10,1912. Serial No. 696,577.

To all whom, it may concern:

lie it known that I, Jesse B. THOMAS, a citizen of the United States, and residentof lloston, county of Sutlolk', State of Massachusetts. have invented an Improvement in l ire-l lxlinguisliers. of which the following description. in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to tire extinguishers ot' the type wherein well known chemicals are brought together in a metal canister pro vided with a removable tluid-tight closure, and the invention relates more particularly to the structure of the closure and the means 'l'or connecting the sealing member or cover with the cap.

The cap is adapted torthreadtal engagement with the neck of the canister, in Well known manner, and herein 1 have connected permanently the cover and the cap so that the said parts may-be rotated relatively and also have a limited relative axial movement.

Such an arrangement prevents any rotativc movement of the cover upon or against the usual packing ring when the canister is be in opened or closed. and it also enables the cover to be lil'ted readily it it should bind, the tilting of the cover being etl'ected by turning baclnvard the cap after relieving the sealing pressure upon the cover.

In my prior U. S. latents Nos. 1,019,859 and 1.022.211 l have shown means for connecting the cover and the cap of a tire eX- tinguisher in such manner that a tree rela-' tive rotation of said parts is permitted, with a limited relative axial movement, and one ot the features of my present invention is a simplified structure whereby such movements are permitted while another object is the provision of means to overcome any tendency of the cover to'rotate upon or with relation to the neck of the canister when the cap rotated to seal the canister or to open it. By eliminating the rotative tendency of the cover at such times I obviate any undesirable rubbing of the packing ring upon the engaging lip or end of the canister neck.

The various novel features of my inven tion will be fully described in the subjoined specification and particularly pointed out in the following claims.

Figure 1 is a vertical diametral section and part elevation of the upper portion of interposed between the opposed bearing surfaces of the cover and cap, shown respectively in Figs. 1 and 2.

Referring to Figs. 1 and 2,1 represents the metallic canister of usual construction, 2 is the upright tubular neck at its open upper end. externally threaded at 3 and forming at its upper end an annular lip 4, all of well known construction.

Referring now to Fig. 1 a circular metal plate 5 constitutes a cover for the canister, said co\er having on its under side an annular undercut seat ti for a suitable packing ring or gasket 7. to contact with the lip 4- when the cover is applied to the canister. The cover has a central. tubular hub 8 projecting from its inner face, externally threaded at 9 and provided with an internal annular shoulder 10. I have shown the circular cap 11 as slightlf arched and impert'orate, and provided with a depending peripheral tlange 1'2 internally threaded for screwing onto the canister neck, the cap hav ing a usual circular rim 13 to facilitate its application to or removal from the canister. The flange 12 surrounds loosely the edge of the. cover, as shown. A tubular, central boss or hub 14 projects from the inner face of the cap and is of such dimensions that it will enter freely the cover hub S and will extend a slight distance beyond the shoulder 10. The cap hub 11 is shown as internally threaded to be engaged by the threaded shank 15 of a connecting member having a cylindrical head 16 provided with a suitable nick 17 by which itcan be fixedly set; into the hub 1 1. The cap and cover are assembled by inserting the hub 14 into the hub 8 of the cover, and then the connecting member is fixed in the hub 14 with its head 16 projecting laterally opposite the shoulder 10 with a clearance therebetivcen, as shown, and as the head 16 fits easily in the lower end of the hub 8 the cap and cover are held from relative lateral movement, but one of said parts. is freely rotatable relatively to the other part. So,- too, while the connecting member unites them permanently the cap and cover have a limited relative axial movement to the extent of the clearance between the shoulder 10 and the head 16.

It is necessary to close fluid tight the cover hub 8, and herein I have shown a cup-- like closure 18 internally threaded to screw tightly onto the threaded portion 9 of the hub 8, and in practice said closure will be sweated or otherwise hermetically closed, as by solder at 19, Fig.1. This arrangement makes the cover 5 fluid tight, so that when it is pressed toward the canister neck 2 the canister will be sealed hermetically, such sealing-being ell'ected when the cap It is i nectmgmember is preferably fixed-permasc-rewed down. I have provided opposed flat and annular bearing surfaces 20, 21 on the cap and cover, respectively, adjacent their peripheries, and instead of permitting said bearlngsurfaces to directly engage l interpose between them loosely a friction reducing member, shown in Fig. 3 as a contrally apertured disk This disk is made of thin sheet metal, the central aperture 23 fitting loosely around the hub 14 to position the disk laterally. When the cap 11 is turned to move the cover 5 toward the canister neck the .ressure is transmitted from the bearing sur ace 20 to the disk, and the latter transmits the pressure to the bearing surface 21 of the cover, the interposition of the disk obviating any tendency of the cover to rotate with the cap. This is an important feature, for as the cover has no tendency to rotate, either when the cap is screwed down or turned backward, there is no rubbing or abrading action between the packing ring 7 and the lip 4, and thereby the life of the packing ring is increased very materially. The closing pressure of the cap is applied, however, to the cover directly above the lip, to obviate any undue strain upon the cover. Should the packing ring stick on the neck, as it will sometimes, espeeially if the canister has been sealed for some time, the permanent connection between the cover and the cap' enables, the cover to be lifted axially when the cap is turned backward to take up the clearance between the head'16 of the connecting memher and the shoulder 10. Any continued backward turning of the cap thereafter will exert a powerful lifting action upon the cover in a direct axial *line, to unseal the canister, without the use of tools or other extraneous devices.

In the embodiment of my invention illustratcd in Fig. 2 the rover 2-2.-

made as an imperloratc plate, but provided as before with an undercut seatdl i'czti: iciti'ng i 7, and said cover has a threaded central pro from its inner fact; projecting from its tubular hub 27 prov nular shoulders 28, 29. The connecting member has a threaded shank 30 and a cylindrical head 31, suitably nicked, as before, and the shank of said member is passed loosely through the hub 27 and screwed tightly into the projection 25 of the cover, the head 31 extending laterally opposite the shoulder 28 with a clearance thercbetween. To protect the connecting member and prevent any rcmovalthereof a metallic disk-like closure 32 is dropped into the open upper end of the hub 27 and u on the shoulder 29, and said closure is fixctl in position in any convenient manner, as for instance by solder at 33. 'lheheaded connently in the projection '25 of the cover, and this may be effected conveniently by solder at 34, between the bottom of said projection and the adjacent end of the shank 251). The cover and the cap are thus permanently and securely connected, but said parts are freely rotatable relatively, and they have a limited relative axial movement due to the clearance between the shoulder 28 and the opposed Ifjace of thehead 31 of the connecting memer. the hub 27 between the shoulders 28, 29 thereof and any impro r lateral movement of the ca relative to t e cover is revented.

, Inasmuc 1 as the cover 24 is in this embodiment of my invention impel-{crate no fluid tight closing of the latter is necessary, as in the construction shown in Fig. 1, but I prefor to close the outer end of the hub 27, to thereby conceal and reventtampering with the connecting member, and also to give a neat finish to the cap.

In Fig. 2 the cap and cover are provided with opposed flat, and annular bearing surfaces 35, 36, adjacent their peripheries, substantially as described with relation to Fi 1,but instead of the friction reducing di therein shown I use a thin, fiat metal ring 37, which is interposed loosely between the bearing surfaces, and for the urpose hereinbefore set forth. To position said ring 37 and maintain it properly between the bearingsurfaces I recess the inner face of the cap, when forming the bearing surface 35, to leave 9. depending annular shoulder 38, which surrounds loosely the periphery of the ring 37 and maintains it in position.

The operation of closing and opening the canister by the structure shown in Fig. 2 is precisely as has been described in detail with relation to the structure illustrated in Fig, i, and will be fully understood without further explanation.

Changes or modifications in details of construction and arrangement. may be made by those skilled in the art without. departing from the spirit and scope of my invention st-t. for! h int-he claims appended hereto. Having fully described my invention,

Said head fits easily into the bore of what I claim as new and desire to secure by Letters Patent is 1. In a fire-extinguisher, a canister having a tubular neck, a cover, cooperating sealing means on the cover and neck, respectively, a cap having a depending perlpheral flange adapted for threaded engagement with the neck, said ca being adapted to depress the cover and e ect sealing of the canister, a permanent connection between the cap and cover comprising an internally shouldered central hub on one, and a headed connecting member having threaded engagement with the other of said parts and extended into the hub, the head of said member extending laterally opposite the shoulder of .the hub with a clearance therebetween, and a permanentclosurefor the 0 en end of the hub adjacent the head ot the connecting member, the latterpermitting free relative rotation of the cap and cover and limited relative axial movement thereof.

2. In a fire-extinguisher, a canister having a'tubular neck, a cover, a cap having threaded engagement with the neck and adapted'toxforce the cover toward the cani'ster neck to seal the same, a central, permanent' connection between said cap and cover comprising a central, internally shoulderedhub on one, and a headed connecting member permanently attached to the other, of said parts and extended loosely into thelhub, the head of said member extending laterally opposite the shoulder with a clearance therebetween, and means to close the open end of the hub adjacent the head of the connecting member,'said member permitting free relative rotation of'the cap and cover and limited axial movement thereof, combined with'a metallic frictionreducing member interposed loosely between the opposed portions of the cap and cover adjacent their peripheries, whereby when the cap is rotated the 3. In ajfire-extinguisher, a canister having a tublfiar neck, a cover having a depending central hub provided with an internal annular shoulder, an imperforate cap having threaded engagement with the neck and adapted to force the cover toward the neck to seal the canister, a central, tubular hub depending from the ca and extended rotatably into the cover hu a connecting member fixed in the inner end of said ca hub and having a head extended laterally elow the shoulder in the cover hub with a clearance therebetween, whereb the cap and cover have a limited relative axial movement and are rotatable freely relatively to each other, and a fluid-tight closure for the inner end of the cover hub adjacent the head of the connecting member.

4. In a fire-extinguisher, a canister having a tubular neck, a cover having a depending central hub provided with an internal annular shoulder, an imperforate cap having threaded engagement with the neck and adapted to force the cover toward the neck to seal the canister, a tubular, internally threaded hub depending centrally from the cap and extended rotatably into the cover hub, a connecting member screwed into the inner end of the cap huband having a cylindrical head extended laterally adjacent the shoulder of the hub with a clearance therebetween, to permit limited relative axial movement of the cap and cover, and a closure for the inner end of the hub to close the same fluid tight.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

. JESSE B. THOMAS.- Witnesses:

J OHN C. EDWARDS, FREDERICK S. GREENLEAF. 

